Band structures and optical properties of GaInAs quantum wires grown by strain-induced lateral ordering

Band structures and optical matrix elements of strained multiple quantum-wires (QWR's) are investigated theoretically via the effective bond-orbital model, which takes into account the effects of valence-band anisotropy and the band mixing. In particular, the Ga$_{1-x}$In$_x$As QWR's grown by strain-induced lateral ordering (SILO) are considered. Recently, long wavelength Ga$_{1-x}$In$_x$As QWR lasers have been fabricated via a single step molecular beam epitaxy technique which uses the SILO process.[1] Low threshold current and high optical anisotropy have been achieved. Multi-axial strains [combinations of biaxial strains in the (001) and (110) planes] for QWR's are considered, Our calculated anisotropy in optical matrix elements (for light polarized parallel versus perpendicular to the QWR's axis) is in good agreement with experiment. We also find that the strain tends to increase the quantum confinement and enhance the anisotropy of the optical transitions.